Did a lot of upgrading recently, Jacob`s wires, Jacob`s ignition, M2 ball bearing twin turbos, M2 ECU, M2 large intercooler, fuel pump upgrade and so forth and everything was running great. Then late last week I started to noticing that the engine was missing if I was just cruising along off the throttle. Doesn`t seem to miss much if at all under acceleration. Changed the plugs, no difference. OK, now what? Injectors maybe?

 

Coils?

 

Hello, anybody out there?

 

Hey Bill ... what does the "missing" sound like?

 

Cpt Bill,
Mine is doing the same thing. Mine seems to miss while maintaining a constant speed under about 30. I recently changed wires an fuel filter and then it started happening. No problem at idle or at WOT or at any load if I am accelerating. I was thinking maybe a loose plug wire.

-Mark

 

Talk to M2 - if you're running too lean at cruise speeds, that could cause the hesitation - I know I've had to add fuel at part throttle on my ECU, to get rid of a hesitation.

Perhaps a dyno plot will help with the diagnosis....

 

I've got the same problem without any upgrades. It just started doing this. Mine does it after the car has been running then turned off and then restarted. Does yours do it right away even after sitting all night? I posted a thread about mine with more specific problems.

If your is like mine it isn't like a lean out as much as it seems like it is about to run out of gas if you idle it is ok and if you put it under load it is ok.

I've cleaned the injectors, added a ground strap. I have not changed the filter or put a fuel pressure gauge on.

I'm thinking it could be the coils getting hot?

Jerry Nuss

 

DK, sounds just like a spark miss.

bbr1, I have talked with M2. It`s hard to diagnose problems over the phone. Doubt it`s running that lean. But I will run that by them. Leaning toward coil.

Jerry, Yes, it seems to do it right away. Like I said leaning toward the coil/s. On Wed. we are changing out the leading coil. Going to try and use a second gen fender mounted coil as they are larger and not engine mounted. So you don`t have a problem with all that heat like on the stock engine mounted one.